O-alkyl-s-phthalimidomethyl alkyldithiophosphonates as insecticides and miticides

ABSTRACT

O-alkyl-S-phthalimidomethyl alkyl dithiophosphonates effective as pesticides in controlling a variety of pest organisms, for example, mites and insects.

Unite States Patent Szabo et al.

[ 1 March 6, 1973 O-ALKYL-S-PHTHALIMIDOMETHYL ALKYLDI-THIOPHOSPHONATES AS INSECTICIDES AND MITICIDES Inventors: Karoly Szabo, Syracuse, N.Y.; John Gary Brady, Kalamazoo, Mich.

Assignee: Stauffer Chemical Company, New

York, NY.

Filed: March 12, 1969 Appl. No.: 813,397

Related US. Application Data [52] US. Cl ..424/200 [51] Int. Cl. ..A01n 9/36 [58] Field of Search ..424/200 [56] References Cited UNITED STATES PATENTS 3,355,353 11/1967 Jamison ..424/200 3,457,283 7/1969 Szabo et al ..260/326 E Primary ExaminerStanley J. Friedman Assistant ExaminerVincent D. Turner Att0rneyWayne C. Jaeschke and Edwin H. Baker [57] ABSTRACT O-alkyl-S-phthalimidomethyl alkyl dithiophosphonates effective as pesticides in controlling a variety of pest organisms, for example, mites and insects.

14 Claims, N0 Drawings O-ALKYL-S-PHTHALIMIDOMETHYL ALKYLDI- THIOPHOSPHONATES AS INSECTICIDES AND MITICIDES This application is a division of copending application Ser. No. 585,247 filed Oct. 10, 1966, now US. Pat. No. 3,457,283, which in turn was a continuationin-part of Ser. No. 442,792 filed Mar. 25, 1965 now abandoned, which is a continuation-in-part application of Ser. No. 265,072 filed Mar. 14, 1963, now abandoned, which was a continuation-in-part application of Ser. No. 121,836 filed July 5, 1961 and Ser. No. 217,302 filed Aug. 16, 1962, now both abandoned.

This invention relates to alkylthiophosphonic acid esters and in particular to O-alkyl-S-phthalimidomethyl alkyldithiophosphonates. The invention is also concerned with the preparation and utility of said organophosphorus compounds as pesticides.

The compounds comprising the instant class of compounds are organophosphorus esters corresponding to the general formula wherein R and R are selected from the group consisting of lower alkyl and chloro lower alkyl of from one to four carbon atoms, inclusive.

In general the new compounds of this invention are prepared by the condensation of a metal salt of a lower O-alkyl hydrogen alkyldithiophosphonate and an N- halomethylphthalimide. The reaction proceeds readily in the liquid phase. Therefore, excellent results may be obtained by carrying out the reaction in the presence of a normally liquid organic solvent. Lower saturated a1- cohols and ketones have been found particularly useful. An organic solvent facilitates processing as well as agitation of the reactants. Temperatures that permit operation in the liquid phase and which are between room temperature and the reflux temperature of the solvent, if any is employed, are operable. Preferably the condensation reaction is carried out at reflux temperature usually at an elevated temperature.

It has been found that the compounds of the present invention are particularly effective as pesticides. They are effective in the control of insects and acarids.

The preparation of the compounds of the present invention may be carried out in accordance with the following non-limiting examples.

EXAMPLE 1 O-Ethyl-S-(phthalimidomethyl)- ethylphosphonodithioate suspended in benzene (100 ml.) and to this mixture was added an equivalent amount (15.0 g.) of O-ethyl ethylphosphonodithioic acid. While the mixture was being stirred, triethylamine (9.2 g.) was added dropwise. This resulted in an immediate and spontaneous reaction with concomitant precipitation of triethyl hydrobromide. The temperature rose to 53C. during the addition, after which the mixture was refluxed for 1 hour. The hydrobromide, obtained in quantitative amount, was separated by filtration. The filtrate was washed with water, 3% NaOH solution, then water again and dried over anhydrous MgSO4. After removing the solvent, 19.5 g. of a straw colored oil was obtained which had an N of 1.6032. The product is obtained as a white solid, when recrystallized from EtOl-l. M.p. 56C.

Using the same procedure of Example 1, but different phosphonodithioic acids, the following additional members of this group have been prepared.

EXAMPLE 2 O-Methyl-S-(phthalimidomethyl)- ethylphosphonodithioate 0 1 CZHs S i -scmN 1 cm0 Prepared in a yield of Off-white solid, m.p. 73C., after recrystallization from MeOH 87C.

EXAMPLE 3 O-Ethyl-S-(phthalimidomethyl)-butylphosphonodithioate Viscous yellow oil, N 1.5850

EXAMPLE 4 O-lsopropyl-S-( phthalimidomethyl)- ethylphosphonodithioate Yellow liquid, N 1.5852

EXAMPLE 5 O-Isobutyl-S-(phthalimidomethyl)- I ethylphosphonodithioate (CIIOzCIICIhO Off-white solid, m.p. 63C.

EXAMPLE 6 O-Methyl-S-(phthalimidomethyl)- chloromethylphosphonodithioate CHQO C II

Amber, viscous oil.

EXAMPLE 7 O-Methyl-S-(phthalimidomethyl)- methylphosphonodithioate O-Propyl-S-(phthalimidomethyl)- ethylphosphonodithioate Yellow liquid, N 1.5921

EXAMPLE 9 O-Isobutyl-S-(phthalimidomethyl)- methylphosphonodithioate White solid, mp 49C.

EXAMPLE l0 O-Ethyl-S-( phthalimidomethyl)- chloromethylphosphonodithioate Nearly colorless, viscous oil, N 1.6070.

As previously mentioned, the herein described alkyldithiophosphonates are useful as pesticides and have been found effective in controlling a variety of pest organisms falling within the lower orders of classification such as mites, insects and the like. For example, the compound of Example 5 was especially effective in controlling the two spotted mite, Tetranychus telarius (Linn.). In the test young pinto bean plants in the primary leaf stage were used as host plants. The young pinto bean plants were infested with several hundred mites. Dispersions of the candidate materials were prepared by dissolving them in a suitable solvent, usually acetone. Aliquots of the toxicant solutions were suspended in water with an emulsifying agent. Test suspensions were sprayed on the infested pinto bean plants. The effect of the candidate compounds was determined by comparison to control plants which had not been sprayed.

In practice the compounds are usually formulated with an inert adjuvant, utilizing methods well-known to those skilled in the art, thereby making them suitable for application. They may be used in the form of emulsions, non-aqueous solutions, wettable powders, vapors, dusts, dips and the like, as may be best fitted to the particular utility. The concentration of a compound of the present invention, constituting an effective amount, and the best mode of administration to a pest or its habitat may be easily determined by those skilled in the art of insect control. The disclosure is not meant to limit the action of the compounds to one particular insect species or the mode of effect thereon.

We claim:

1. An insecticidal and miticidal composition comprising an inert adjuvant and an insecticidally or miticidally effective amount of a compound of the formula wherein R and R are selected from the group consisting oflower alkyl and chloro lower alkyl.

2. The composition according to claim 1 wherein R is lower alkyl and R is lower alkyl, each having one to four carbon atoms, inclusive.

3. The composition according to claim 1 wherein the compound is O-ethyl-S-(phthalimidomethyl)- ethylphosphonodithioate.

4. The composition according to claim 1 wherein the compound is O-ethyl-S-(phthalimidomethyl)-butylphosphonodithioate.

5. The composition according to claim 1 wherein the compound is O-isobutyl-S-(phthalimidomethyl)- ethylphosphonodithioate.

6. The composition according to claim 1 wherein the compound is O-isopropyl-S-(phthalimidomethyl)- ethylphosphonodithioate.

7. The composition according to claim 1 wherein the compound is O-ethyl-S-(phthalimidomethyl)- chloromethylphosphonodithioate.

8. The method of killing insect and mite pests comprising applying to the insect or mite pest habitat an insecticidally or miticidally effective amount of a compound of the formula wherein R and R are selected from the group consisting of lower alkyl and chloro lower alkyl.

9. The method according to claim 8 wherein R is lower alkyl and R is lower alkyl, each having one to four carbon atoms, inclusive.

compound is O-ethyl-S-(phthalimidomethyl)- chloromethylphosphonodithioate. 

1. An insecticidal and miticidal composition comprising an inert adjuvant and an insecticidally or miticidally effective amount of a compound of the formula
 2. The composition according to claim 1 wherein R is lower alkyl and R1 is lower alkyl, each having one to four carbon atoms, inclusive.
 3. The composition according to claim 1 wherein the compound is O-ethyl-S-(phthalimidomethyl)-ethylphosphonodithioate.
 4. The composition according to claim 1 wherein the compound is O-ethyl-S-(phthalimidomethyl)-butylphosphonodithioate.
 5. The composition according to claim 1 wherein tHe compound is O-isobutyl-S-(phthalimidomethyl)-ethylphosphonodithioate.
 6. The composition according to claim 1 wherein the compound is O-isopropyl-S-(phthalimidomethyl)-ethylphosphonodithioate.
 7. The composition according to claim 1 wherein the compound is O-ethyl-S-(phthalimidomethyl)-chloromethylphosphonodithioate.
 8. The method of killing insect and mite pests comprising applying to the insect or mite pest habitat an insecticidally or miticidally effective amount of a compound of the formula
 9. The method according to claim 8 wherein R is lower alkyl and R1 is lower alkyl, each having one to four carbon atoms, inclusive.
 10. The method according to claim 8 wherein the compound is O-ethyl-S-(phthalimidomethyl)-ethylphosphonodithioate.
 11. The method according to claim 8 wherein the compound is O-ethyl-S-(phthalimidomethyl)-butylphosphonodithioate.
 12. The method according to claim 8 wherein the compound is O-isobutyl-S-(phthalimidomethyl)-ethylphosphonodithioate.
 13. The method according to claim 8 wherein the compound is O-isopropyl-S-(phthalimidomethyl)-ethylphosphonodithioate. 